Prostheses are applied to the human body in order to replace amputated and/or deformed portions of the anatomy, and most often but not limited to the limbs. Essentially, it is missing portions that are to be simulated and fitted to the remaining parts or existing parts of the body. Consequently, there are contours of peculiar and abnormal configurations that must be matched and fitted to, and these can change in time. That is, there may be local swelling or shrinking of muscle and fatty tissue, and the underlying bone structure can change. Therefore, it is a general object of this invention to provide a prosthesis that is acurately fitted to the contours of the body, natural or abnormal, and which can be subsequently adjusted in its fit as circumstances require.
It is the limbs of the body that are most often injured and which are very necessary as members used in manipulation and ambulation. Therefore, this invention will be described as it relates to the arms and legs of amputees or the like, where a "stump" of the body limb is fitted for the application or the attachment of a prosthetic limb. Accordingly, it is an object of this invention to accurately fit a "socket" to the stump of a limb, not to exclude the fitting of any suitable prosthetic piece or form to the exterior of the body. In practice, an arm may be severed at or between the shoulder, elbow or wrist processes, and a leg may be severed at or between the hip, knee or ankle processes. The point of severence or amputation can be deliberate or by accident and in any case results in a "stump" of distinctive configuration that must be fitted to in each instance. Healing of the flesh over the terminated bone structure varies with each removal of the anatomy, and the prosthesis must be made special and/or customized to the individual stump or area to which it is to be attached. It is an an artcle of manufacture that inherenly conforms to body contours and configurations for the comfortable application and attachment of prostheses.
An object of this invention is to reduce expenditure in the process of producing prostheses conforming to body contours. Heretofore, inflexible firm prostheses have been made of materials that become permanent in shape and cannot be modified, except by removing or adding material thereto. For example, a limb socket made of resin impregnated fiberglass can be filed away or built up with added layers, but only with the expertise of an experienced craftsman; and even then the results are doubtfully beneficial. Furthermore, such individually prepared laminiform structures are expensive and their preparation is time consuming, requiring repeated sittings of the patient with the technician and at time intervals in order to allow for completion time in the finish work required. With the present invention a heated plastic member is prepared and fitted over a model made of a person's body part to be fitted. As shown herein the plastic member is a heated cone to be fitted over the model of a person's stump. The temperature applied is greater than that which can be tolerated by the skin of a person, and consequently a model of the body part or stump is employed in the process. The heated plastic conforms to the precise contours of the model and retains the model form when cooled to normal room temperature, at which time it is immediately fitted to the person and the required prosthesis features attached as may be required.
It is an object of this invention to provide a prosthesis that can be reshaped or reformed from time to time as required according to changes in the body part to which it fitted. To this end a partially cured plastic material is employed in forming the prosthesis, which is reformable at raised temperature below the curing temperature of said material, and which is structurally stable at lower normal ambient temperatures. The reforming temperature is greater than that which can be tolerated by the patient, and accordingly the model is retained for subsequent forming and reforming as the case may be. In the case of reforming, the model is reshaped, and being of plaster or the like, can be easily reshaped in a short length of time, while the patient is waiting. And, the prosthesis being of cured reshapable plastic material, it too can be quickly heated and easily reshaped over or to the modified model in a short length of time.